Head ct is equivalent to the radiation dose of head CT every 8 months.

Imaging examination is an important auxiliary examination in clinic at present, which can effectively help doctors to diagnose or differentiate diseases. Imaging examination includes ultrasound, traditional X-ray examination, CT, magnetic resonance imaging and nuclear medicine examination. Ultrasound is based on the reflection principle of sound waves, and magnetic resonance imaging is based on the principle of nuclear magnetic resonance, which will not cause harm to the body. X-ray examination has ionizing radiation, which may cause harm to the body.

A head CT is about 8 months of daily radiation.

Traditional X-ray examination, also called X-ray radiography, has been basically replaced by CR or DR, which penetrates human tissues to obtain two-dimensional images of internal organs. This kind of examination is painless. CT examination is like a multi-nanometer circle. When the patient enters this multi-nanometer circle, X-rays will radiate around it, so as to obtain the sectional image of the human body and reconstruct the three-dimensional structure. This kind of examination can get more information about internal organs.

Both tests use X-ray imaging. X-ray is a kind of electromagnetic wave with strong penetrating power, so it may penetrate the DNA chain in the cell when passing through the human body, leading to abnormal repair of the DNA chain. At the same time, it also has ionization effect, which leads to ionization of components in the body and causes harm to the body.

Fortunately, X-ray photography and CT only use X-rays, and they are artificially made, which will only be produced after electricity is applied. Therefore, there is no radiation in the radiology studio. Only the radiologist will emit radiation at the moment of shooting, and then the radiation will disappear without a trace.

So how much radiation will the human body receive when doing radiation inspection? Roughly converted into the exposure time in daily life, if the radiation amount in normal environment 1 day is taken as the benchmark, the first chest radiograph is the same as the benchmark. Head CT is equivalent to 8 months of daily radiation, and abdominal CT is equivalent to 20 months.

These values may be shocking, but in fact, the specific results of medical X-ray irradiation are inconclusive. However, it is undeniable that large-scale population surveys have confirmed that X-rays will increase the probability of human cancer, especially children.

If radiation is dangerous, then why radiation? Through imaging examination, doctors can diagnose, locate, quantify and even characterize the disease, and can determine the affected parts and prognosis of the patient's disease. Therefore, doctors usually decide whether to carry out radiological examination on the principle of examination and less damage. Moreover, pediatricians will choose the most beneficial and least harmful examination methods for children in the existing imaging examinations, such as harmless ultrasound examination for solid organs and urinary system and harmless magnetic resonance imaging examination for central nervous system. The child is in an active period of growth and development, and all kinds of glands are sensitive to X-rays. During the examination, except for the exposed part, the doctor will protect the child's thyroid and gonads. Because the eye crystal is also sensitive to x-rays, it will also be shielded.